looks like a 4 ga rifle cartridge but isn't and you wonder how it would perform on elephant in a rifle

here with family and friends

4 ga plastik shell, 1" Nordenfelt, 26,5 mm signal flare and 14,5x114 russian

the Nordenfelt have a 30,28 mm rim, 2,21 mm thick, base 27,20mm, mouth 26,16 mm and 96,66 mm long so no real 4 ".
maximum for the 4 ga is 30,45 mm rim, 3,25 mm thick, base 27,60, mouth 26,20 mm so yes the round will maybe fit into the chamber of a 4 ga. don't hope to find brass for loading ammo for a 4 ga, they are rare like hen's ivory

DWM Karlruhe made

steel bullet weight 205 gramm not grains, having a strange hollow base

another one in the net, loaded
https://www.youtube.com/watch?v=KbAdnUHoFH0